Treatment training manual

3.19 Treatment failure

Treatment failure is defined in different ways.

This can vary by country. This depends on the tests that are available.

Viral failure

Viral failure is defined as:

  • Viral load never becoming undetectable in a certain time.
  • Viral load becoming detectable after previously being undetectable.

Both cases chow that ART might not be working.

Viral failure is not linked to feeling ill.

Clinical failure

This is when you get symptoms (ie other illnesses). It means that the drugs are not stopping you from getting ill. This is called clinical failure.

How to manage treatment failure varies in different countries.

It depends on which test and drug choices are available.

Managing treatment failure

Before changing ART it is important to find out why treatment failed.

  • Was this related to adherence? Or being given the wrong ART? Or that you have stopped taking ART?
  • Is is because of drug resistance. Or because the treatment was not potent enough. Or because the drugs were being poorly absorbed.

Management of treatment failure is different depending on which country you live in. This is related to whether viral load tests are easily available..

  • Viral failure is used to decide when to change ART in high-income countries. This is when there is access to viral load tests and/or there are several options for a new combination.
  • Clinical failure is used to decide when to change treatment in many low- and middle-income countries (LMICs). This is when viral load tests are not available and/or there are limited options for a new combination.

When there are new treatment options, then changing all three drugs to a new combination is recommended.

Low level increases in viral load are often just blips (one-off unusual results) and often go down by themselves.

Blips do not count as treatment failure.

Blip compared to viral rebound

Virological failure usually occurs first. It can sometimes take months for this to lead to clinical failure.

Management of treatment failure is a specialised area, and approaches changes based on new research.

Further reading

i-Base produce a detailed guide to changing treatment (August 2021).

This is a separate resource to the advocacy manual and is based on virological failure. It has been translated into other languages.

Last updated: 1 August 2021.